Spiders

Great spiders, able to speak among themselves and hating the light as Orcs do. They are counted the children of Ungoliant, and in the First Age they kept to the south of Middle-earth, bred from the spider-creatures of the Ered Gorgoroth. By the Third Age they had spread widely, and when a shadow settled on Greenwood the Great many of them came to live under its trees, so that the wood was renamed Mirkwood. Tolkien put spiders into his stories again and again, always as enemies. The tale that a tarantula bit him as a child is not the reason for it; the fear belonged to his son.